Nicolas rappez



N. RAPPEZ.

HAMMER FOR COMPACTING SAND IN MOLDS.

APPLICATlON FILED NOV. 22. 19H3. 1,316,973. Patenasept. 23, 1919.

wom/dro@ A04 @lne/(Mams MOC? I TI'IB CULUMBIA PLANNUUHAII C0 WASHINGTON,D. C.

UNITED STATES PATENT OFFICE.

NICOLAS RAPPEZ, OF ST. PIERRE, BELGIUM, ASSIGNOR TO ACIER/IES ETFONDERIES DART DE HAINE SAINT PIERRE ET METALL'URGIQUE LILLOISE, SOCITANONYME, OF ST. PIERRE, BELGIUM.

RAMMER FOR GOMPACTING SAND IN MOLDS.

Specification of Letters Patent.

Patented Sept. 23, 1919.

Application led November 22, 1916. Serial No. 132,751.

. pacting Sand in Molds, of which the following 1s a specification.

My invention relates to a rammer for compacting sand in molds. Oneobject of my invention is to provide a rammer of simple and practicalconstruction, adapted to secure a technically perfect compacting of thesand in the mold or in other words to secure a more or less importanteompacting of the sand at given places of the mold while maintaining acertain porosity at other places in order to permit the escape of thegas and to facilitate the shrinkage of the metal when it cools.

Another object of my invention is to provide a rammer which will beespecially adapted for the manufacture of castings in series, thatl isto say securing'always the same action in different molds usedsuccessively and at the same predetermined places in said molds.

With these objects in View, my invention essentially consists in certainnew combinations and arrangements of parts which will be hereinafterfully described and pointed out in the appended claims.

In the annexed drawing which shows as an example one embodiment of myinvention in its application to the molding of a given casting,

Figure l is a side elevation of the new rammer.

Fig. 2 is a side elevation showing separately the piece which is to bemolded, a wheel in the present instance.

Fig. 3 is a top View, corresponding to Fig. 1 showing, as an example,how the several elements of the rammer are arranged, in the examplechosen, in order to correspond to the shape of the pattern which is tobe molded.

a is a supporting member such as a plate or disk, which can be massive,hollowed or of any other form. b are rods or bars Which'are rigidlyattached to the supporting member a. Each of the said bars is providedor formed at its lower end with e ramming head o, the form of whichvaries according to the place of the mold which is to be acted upon;said ramming heads c can also be circular in shape as it is shown in c1when they have to act in an angle, for example, or square as it is shownat c2, rectangular as shown at c3 or trapezoidal as shown at c4 or ofany other shape according to the shape of the several parts of thepattern which is to be molded.

The rods or bars Z) have different lengths as it is shown in Fig. l,according to the relief of the several parts of the pattern model d, thelongest rods corresponding to the parts of the model which have theminimum of relief and the shortest rods corre-y sponding to the part ofthe pattern, such as the part d1, for instance, having the greatestrelief or the greatest height.

Said rods b are attached to the plate or disk a and are spaced from oneanother according to the necessities of the molding operation; theirnumber varies according to the shape of the pattern so as to secure, atall the places where they have to act upon the sand, a convenientcompacting of said sand in the mold box against the several faces of thepattern.

To make use of a rammel' composed as described, the pattern being placedin a mold boX in a well-known manner, sand is placed in the mold box tothe required height; an alternative movement in vertical direction, thatis to say an up and down movement is then given to the plate a so as tocause the ramming heads c to strike on the sand contained in the moldbox. This up and down movement can be produced manually or mechanicallyaccording to the dimensions of the apparatus; to this end, the plate amay be provided with a bar c adapted to be grasped by hand or to befixed in a suitable actuating machine,

As a consequence of the up and down movement, all the ramming heads cact simultaneously by percussion or by presure, thus compacting the sandin the mold- As it will be obvious, in such conditions, a rammercombined for a given attern will suit for the molding of a mulptiplicityof pieces of the same pattern or in other words can be used forcompacting successively the sand in a series of mold boxes withoutposability that any derence whatever be progenerally produce a greaterthe upper part of the moldV and duced from one mold box to the other,under the only, condition that the pressure exerted on the plate a bethe same in each operation.

The rods b are preferably fixed or attached to the plate a so as to beremovable in such a manner that with an appropri-v ate number of sets ofrods Z), hav-incr variableJ lengths andrramming-ends c oi variableshape, all the necessary combinations can be realized to suit theseveral cases which can Vbeencountered in practice. The rammer composedfor the molding of Va given pattern may then be employed, without anymodiication or adjusting, for the molding of anY iniinity of pieces ofthe same pattern.

The rammer described has the advantage to secure a uniform compactingaction alvways at predetermined places, a result which cannot beobtained with the devices hitherto used, for instance with theV rammingplates, (plane or embossed) which do Vnot allow of maintaining at givenplacesjthe necessary Yporosity to assist the escape of the Y gas duringthey casting, and the shrinkage solidity of the pattern which must berepaired or renewed if the danger of 'producing alterated castings willbe avoided-5 Such inconveniences cannot be encountered with a device asdescribed, each ramming head c Voi a given rod b acting evidently alwaysat a predetermined place.V Y

1I amaware that the use of ramming rods coperating with a common supportis not new in devices lof this kindgin the devices already known,however, 'the rods had `always the same length and the ramming heads at.their ends, had all the same shape; said rods further were acting onlyunder the action of their Aproper* weight and their action upon the sandwas the same on all'the places of the mold box, the common support Vforsaid rods serving only as a guid- Gopes of this patentV may be obtainedfor compression at ing device and to produce their common upwardmovement, Y Y y Y 4 Y y Such a construction doeslnotuallow, Vlike thataccording to Amy invention, ateChni- 1 cally perfect compacting of thesand in the mold boX,.if itis considered that, in order to avoid flawsand cracks or other defects, itis necessary that for each given piece,the compacting beV more or less important at given-places while; :acertain vporosity is escape of the gas and to Vpermit the yshrinkage ofthe metal during. its cooling. Devices maintained at other places toallow theof this kind, further do not'secure an identit cal action fromoneimold to another' as there Vis no guarantee whatever that the vactionof the ramming heads will alwaysv be the 'same 4at the same places,

hat I Vclaim is:

l. In a rammer, a support, a plurality of ramming elements mounted onsaid support reproducing in outline 4the casting to be formed, saidramming elements comprising rodsof varying'lengths, heads at the ends ofsaid rods, said heads having varying angular and circular shape,theshapeof the Y heads .and lengths of the rods depending upon the patternaround which the sand lis to be tamped,'certain of said ramming elementsbeing spaced apart relative tolone anotherand of shorter length thancalledfor by the pattern at certain places inl-the t'pattern wheredefiniteness of design may be sacrificed, there to provide a porous zonefor the escape 'o-gasduring casting and to facilitate the shrinking` ofthe metal `when it cools.V l Y '2. I n a rammer, a support, apluralityfoi1 ramming elements mounted on said support,

reproducing in outline the casting -to be formed, certain of saidramming elements being spaced relative to one another and of shorterlength than called for by the design to provide a porous Zone at suchplaces where definiteness of design maybe sacriiiced, there to provide:forfthe escape of the gas during casting and to facilitate theshrinking'of the metalwhen it cools."

'In testimony whereof I have aiiiXed my signature in presence of rtwowitnesses.

NIQOLASV RAPPEZY,

Witnessesz' Y i y i CHARLES YRov N'AsMirH, JAYNE Benn.V

ve cents eachr,"iby addressing, the' VGommssioner Vof Patents,Washington, D. C. f

